Brazil, Uruguay: Subtropical Storm Yakecan forecast to impact southern Brazil and Uruguay through at least May 18

Event

Subtropical Storm Yakecan is forecast to bring heavy rainfall, thunderstorms, and strong winds to southern Brazil and Uruguay through at least May 18.

As of late May 17, Brazil's National Institute of Meteorology (Inmet) has issued the following warnings:

• Red (highest level on a three-tier scale) warnings for coastal winds: Coastal areas of Rio Grande do Sul and Santa Catarina states.

• Orange warning for heavy rainfall: Parts of eastern Rio Grande do Sul and far southeastern Santa Catarina states. Between 3-6 cm (1-2 inches) of rain per hour or 5-10 cm (2-4 inches) of rain per day and winds of 60-100 kph (37-62 mph) are forecast.

• Orange warning for gales: Eastern Parana, Rio Grande do Sul, and Santa Catarina states. Strong winds of 60-100 kph (37-62 mph) are likely.

• Orange warning for snow: Southern Parana, far northeastern Rio Grande do Sul, and central Santa Catarina states. Snow of 5-20 cm (2-8 inches) is forecast; hazardous travel conditions are likely.

The Uruguayan Institute of Meteorology has issued a yellow (lowest level on a three-tier scale) alert for strong and persistent winds over southeastern Uruguay. Winds of 50-60 kph (31-37 mph) with showers are forecast. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.

Reports indicate that at least 226,000 homes are without electricity in Rio Grande do Sul State, Brazil, as of late May 17. Authorities did not immediately provide an estimation of when power would be restored. The National Department of Transport Infrastructure (DNIT) has advised motorists with light vehicles to avoid traveling on federal highways through May 18 due to hazardous travel conditions. One fatality has been reported north of Montevideo City, Uruguay, due to a fallen tree. Almost 24,000 homes in Uruguay are without power as of May 17.

Hazardous Conditions
Sustained heavy rainfall could trigger further flooding in low-lying communities near rivers, streams, and creeks. In developed areas with easily overwhelmed stormwater drainage systems, additional urban flooding is also possible. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides remain possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil. Power outages and disruptions to telecommunications services are likely where significant flooding, landslides, or strong winds impact utility networks.

Transport
Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel in affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather could also trigger intermittent flight delays and cancellations at airports in the region, though these are unlikely to be severe or prolonged. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and track inundation. Localized business disruptions may occur in low-lying areas.

Advice

Monitor local media for updated emergency and weather information. Seek updated information on weather and road conditions before driving or routing shipments through areas where severe weather is forecast. Plan accordingly for potential delivery delays if routing shipments by truck through affected areas. Do not attempt to drive through flooded areas. Confirm flights. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Brazilian National Institute of Meteorology
Uruguayan Institute of Meteorology